The server then sets up connections to all running emulator/device
instances. It locates emulator/device instances by scanning
odd-numbered ports in the range 5555 to 5585, the range used by
emulators/devices. Where the server finds an adb daemon, it sets up a
connection to that port. Note that each emulator/device instance
acquires a pair of sequential ports — an even-numbered port for
console connections and an odd-numbered port for adb connections. For
example:

Emulator 1, console: 5554

Emulator 1, adb: 5555

Emulator 2, console: 5556

Emulator 2, adb: 5557 ...

The ADB server only checks for devices by scanning odd-numbered ports in the range 5555 to 5585 ( 30 ports in total) and assigns 2 ports for each device. Is ADB capable of accepting more than 15 Android Devices (15x2 ports) or can I connect more devices on the same computer? I think it is impossible to run more than one ADB servers on the same machine.

Is it possible to access a not rooted device over wifi?
–
salamisJun 2 '12 at 20:04

No, the device must be rooted, and you must change the settings from a root prompt on the device, or adb shell must give you a root prompt (my phone usually does not, though it has su installed). I don't know how to get back to USB when adb shell does not give a root prompt, short of rebooting.
–
ashley willisJun 2 '12 at 21:46